Element for retaining the front of a boot on an alpine ski

ABSTRACT

An element for retaining a boot on a ski provided to releasably retain one of the ends of a boot by means of a jaw movable laterally on either side of a centered position aligned with a longitudinal and vertical median plane of the retaining element, and a compensating mechanism acting on the jaw or its return mechanism so as to further facilitate its opening, where the compensating mechanism includes two active elements, either of which are biased as a function of the side where the jaw moves with respect to the vertical and longitudinal median plane. The two active elements are asymmetrical with respect to the longitudinal and vertical median plane, such that the compensating mechanism is more or less active depending on the active element biased as a function of the side on which the jaw moves.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an element for retaining thefront of a boot on an alpine ski.

[0003] 2. Description of Background and Relevant Information

[0004] An element of the above-mentioned type is provided to retain thefront of the boot in cooperation with a rear element, and to release theboot in the case of excessive force.

[0005] The forces exerted between the boot and the ski have a pluralityof force or moment components which can be resolved in relation to axes,one of which is the vertical axis of the leg, and another is thelongitudinal axis defined by the foot.

[0006] One of the main components is the moment in relation to thevertical axis of the leg. This component induces a torsion in theskier's leg, which is found at the level of the knee joint.

[0007] It has been known for a long time that the intensity of thestresses which a knee can withstand without damage depends on thedirection in which the leg is biased in torsion. A knee is more fragileduring a bias that drives a foot rotationally inward, i.e., toward theother foot.

[0008] Thus, a retaining element is known from the published PatentApplications Nos. FR 1 503 847, FR 1 503 848, FR 1 503 849, whoserelease threshold is different depending on the direction in which theboot biases it. More recently, the Applications FR 2 722 372, FR 2 722373, FR 2 722 374 and U.S. Pat. Nos. 5,615,498, 5,639,108, 5,702,119disclose constructions related to this problem. For these retainingelements, the release threshold is higher on the side where the knee ismore resistant, and lower on the side where the knee is less resistant.

[0009] Such devices yield satisfactory results insofar as the releasethresholds are better adapted to the skier's morphology.

SUMMARY OF THE INVENTION

[0010] An object of the invention is to further improve the performancesof the front retaining elements in this function of adapting to theskier's morphology.

[0011] Other objects and advantages of the invention will becomeapparent from the description that follows.

[0012] The retaining element according to the invention is provided toreleasably retain one of the ends of a boot by means of a laterallymovable jaw on either side of a centered position aligned with alongitudinal and vertical median plane of the retaining element, inresponse to a force having a lateral component oriented in eitherdirection against the resistance of an elastic return mechanism. Itincludes a compensating mechanism acting on the jaw or its returnmechanism so as to further facilitate its opening, the compensatingmechanism having two active elements either of which is biased as afunction of the side where the jaw moves with respect to the verticaland longitudinal median plane.

[0013] The two active elements of the invention are asymmetrical withrespect to the longitudinal and vertical median plane, such that thecompensating mechanism is more or less active depending on the activeelement biased as a function of the side on which the jaw moves.

BRIEF DESCRIPTION OF DRAWINGS

[0014] The invention will be better understood from the followingdescription, with reference to the annexed drawings that are an integralpart thereof, and in which:

[0015]FIG. 1 schematically shows a side and cross-sectional view of aretaining element according to a first embodiment of the invention.

[0016]FIG. 2 is a front view of the device of FIG. 1.

[0017]FIGS. 3 and 4 schematically show a second embodiment of theinvention.

[0018] FIGS. 5-7 relate to another embodiment of the invention.

[0019]FIG. 8 is an alternative embodiment of the device shown in FIG. 6.

[0020] FIGS. 9-11 schematically show another embodiment of theinvention.

[0021]FIGS. 12 and 13 relate to another embodiment of the inventionapplied to a rear retaining element.

DETAILED DESCRIPTION OF THE INVENTION

[0022] The embodiment of the invention illustrated in FIGS. 1 and 2belongs to a field of construction like that of the binding disclosed inPatent Application FR 2 533 833, the disclosure of which is herebyincorporated by reference thereto in its entirety.

[0023]FIG. 1 shows a front retaining element 1 provided to retain thefront of a boot. This element includes a retaining jaw 2 that forms anintegral assembly with a body 3. The body 3 is movably mounted so as torotate about a substantially vertical pivot 5. The pivot is provided tobe affixed to the gliding board. The pivot has a flat portion 7 in itsportion oriented forwardly. A piston 8 is biased by a spring 9 supportedagainst the flat portion 7. The piston and the spring are housed in thebody. In a known fashion, the piston cooperates with the flat portion toelastically return the body in a resting position that is centered onthe longitudinal and vertical median plane of the retaining element, thelatter containing the longitudinal axis defined by the ski. However, thejaw and the body can move away on both sides from this position againstthe return force of the spring 9.

[0024] A support device is further provided for the boot. This deviceincludes a support element 10 mounted so as to oscillate about ahorizontal and transverse axle 12. The support element is extendedforwardly beyond its axle 12 by an arm 13 whose end is engaged beneaththe body behind the pivot 5. Preferably, a roller 20 movable about alongitudinal axis is located at the end of the arm 19. When the arm isin the resting position, the support element is kept raised with respectto the upper surface of the ski due to the support of the roller 20against the base of the body 4.

[0025] In this area, the body 4 has a ramp 21. The ramp 21 includes twolateral surfaces 21 a, 21 b, and a central edge or surface 21 c.

[0026] The two ramps 21 a and 21 b are located on both sides of thelongitudinal and vertical median plane of the retaining element, whenthe jaw is in its centered position, and they are oriented top downtoward the edge 21 c, which is located in the median longitudinal andvertical plane. When the body is in the centered position aligned on thelongitudinal axis defined by the ski, the roller 20 is in supportagainst the edge 21 c. If the body pivots on either side with respect toits centered position, the roller describes either one of the surfaces21 a or 21 b.

[0027] The support of the boot on the support element 10 is transmittedby the roller to the ramp, which induces on the body a lateral forcethat is added to the lateral force exerted by the boot on the jaw.

[0028] During a torsional front fall, in particular, this mechanismcompensates for the frictional forces that exist between the boot soleand its support element, and which tend to delay the release of theboot.

[0029] Possibly, one can provide the edge 21 c to be broken along a flatportion of small width to provide a small zone on both sides of thecentered position where the compensating mechanism is inactive.

[0030] According to the invention, and as is visible in FIG. 2, thesurfaces 21 a and 21 b of the ramp 21 do not have the same gradient,such that the compensating effect is more pronounced on one side than onthe other.

[0031] In the embodiment shown, the surface 21 b located on the rightside in the figure has a higher gradient than the surface 21 a. Underthese conditions, if the boot drives the jaw on the left side in thefigure, a same support of the boot on the support element 10 induces amore substantial compensation on this side than on the other. This jawpivoting side corresponds to the leg twisting direction where the kneeis the most fragile.

[0032] For a pair of retaining elements associated with a pair of skis,the ramps of the front elements are symmetrically arranged with respectto one another, the surfaces with a higher gradient being inward, andthose with a lower gradient being outward, considering the constructionof the front element that has been described.

[0033] It must be noted that the surfaces 21 a and 21 b of the ramp arenot necessarily rectilinear or planar. One and/or the other of the twosurfaces could be incurved so as to induce a certain progressiveness inthe action of the compensating mechanism as a function of the lateraldisplacement of the jaw.

[0034]FIG. 3 shows a second embodiment of the invention. Theconstruction shown therein belongs to a field of construction like thatof the binding disclosed in Patent Application FR 2 248 062 and U.S.Pat. No. 3,909,029, the disclosures of which are incorporated byreference thereto in their entireties.

[0035] The retaining element is a front element having an integral orone-piece body 25 and jaw 26. The body is pivotally mounted on aball-and-socket joint including a pivoting head 27 provided to beaffixedly assembled to the ski and housed in the body 25. The return ofthe body in its centered position is ensured by a ball 28 pushed by aspring 29 back into a recess 30 of the pivoting head.

[0036] The jaw is adapted to pivot laterally on both sides of thecentered position, with respect to the pivoting head. The jaw can alsorise vertically as a function of the forces exerted by the boot.

[0037] The vertical movement of the jaw is controlled by a ramp 32located at the front of the spherical head. The ramp is provided to beaffixed to the ski, it includes two lateral surfaces 32 a, 32 b thatconverge base up toward a central flat portion 32 c located in thevertical median plane of the retaining element. A rotatable roller ismounted at the front of the body 25. It rests on the ramp 32. The roller34 could be replaced by another equivalent structure.

[0038] In the centered position of the jaw, the roller is in contactwith the flat portion 32 c. When the jaw is driven by the boot on eitherside of its centered position, the roller describes either one of thesurfaces 32 a or 32 b, if the force exerted by the boot on the jaw has avertical component in addition to the lateral component.

[0039] When the roller describes either one of the two inclined surfacesof the ramp, the vertical component which the boot exerts on the jaw istransformed in the area of the roller into a lateral component thatfacilitates the lateral pivoting of the body. Thus, one has acompensating mechanism that is active in a torsional rear fall. Thismechanism compensates for the friction forces between the jaw and theboot sole which can delay the release of the boot.

[0040] According to the invention, the two surfaces 32 a and 32 b of theramp have a different gradient, such that the compensation is moreactive on one side of the centered position with respect to the other.

[0041] For a pair of retaining elements associated with a pair of skis,the ramps of the front retaining elements with more substantial gradientare located toward the inside, and the ramps with lower gradient towardthe outside, considering the element construction that has beendescribed.

[0042] FIGS. 5-7 relate to another embodiment of the invention and, moreparticularly, to a field of retaining element like that described in thePatent Application EP 31 740 and U.S. Pat. No. 4,398,747, thedisclosures of which are incorporated by reference thereto in theirentireties.

[0043] Thus, FIG. 5 shows a front retaining element having a body 35provided to be fixedly mounted on the ski.

[0044] A jaw 36 is movably mounted with respect to the body about asubstantially vertical pivot 37.

[0045] A piston 39 and return springs 38 are housed in the body. Thesprings push the piston back against a flat portion 40 of the jawlocated at the front of the pivot 37. The springs and the piston returnthe jaw 36 in a centered position on the longitudinal axis of the ski.From this position, the jaw can pivot laterally on either side as afunction of the forces of the boot.

[0046] The retaining element further includes a support element 43provided to support the boot sole. The support element here is laterallymovable. To this end, according to the embodiment shown, it is guidedalong a rail 44 fixed to the ski. The rail can be linear and transverseor, as shown, incurved along an arch of a circle centered approximatelyin the area of the heel of the boot so as to follow the trajectory takenby the front of the boot during a lateral release.

[0047] A roller or another equivalent structure is mounted at the end ofan arm 47 that extends on the front of the support element, in thealignment of its vertical median plane. The roller is in support againstthe ramp 48 of an element which is in the form of a drawer 50 slidablymounted along the longitudinal direction of the ski. On the rear, thedrawer-like element 50 has a return 51 that is inserted between the flatportion 40 of the jaw 36 and the piston 39.

[0048] The ramp 48 includes two surfaces 48 a and 48 b inclined front torear, which converge toward a central edge 48 c aligned on the verticaland longitudinal median plane of the retaining element.

[0049] In the case where the boot biases the jaw laterally, and where itexerts a substantial pressure on its support element, it tends to drivethe support element along. The thrust of the roller 46 on either one ofthe surfaces of the ramp is transmitted to the spring in the form of alongitudinal force that proportionately relieves the force which the jawmust overcome to pivot laterally. Such a mechanism compensates for thefrictional forces that exist between the boot sole and its supportelement.

[0050] According to the invention, the two surfaces of the ramp 48 havea different inclination with respect to the longitudinal median plane ofthe ski, so that the compensating system is more or less activedepending on the pivoting side of the jaw. In the embodiment shown, thesurface 48 a is less inclined than the surface 48 b. As a result, thecompensation is more active if the boot drives the support elementtoward the top in the figure rather than toward the bottom.

[0051] For a pair of skis equipped with retaining elements, the ramps ofthe front elements are symmetrically arranged with respect to oneanother, and the retaining elements are arranged such that the leastinclined surfaces are inward, and the most inclined surfaces areoutward.

[0052] This embodiment is adapted to have alternatives. For example, asschematically shown in FIG. 8, rather than the ramp having surfaces ofdifferent inclination, one could have intersecting levers 51 and 52acting on the drawer-like element 53 with different lever arms. Thedifference in lever arm can be obtained either in the area of thejournal axes of the levers, or in the area of their support on thedrawer-like element or the movable support element.

[0053] FIGS. 9-11 show another embodiment of the invention and, morespecifically, one belonging to the field of construction like thatdisclosed in the published Patent Application No. WO 85/03451 and U.S.Pat. No. 4,660,849, the disclosures of which are incorporated byreference thereto in their entireties.

[0054] The construction of this front retaining element includes a body55 provided to be affixed to the ski, and a retaining jaw 56 movablewith respect to the body. The jaw is journalled at the end of two arms57 and 58, which are themselves journalled with respect to the body,such that the four journal points of the arms and of the jaw form thefour vertices of a variable quadrangle. The jaw journalled at the end ofthe arms can move laterally with respect to the body on both sides of acentered position. As shown in FIG. 9, the body covers the arms and aportion of the jaw with a cover 60. A return mechanism, not shown,opposes an elastic resistance to a displacement of the jaw on both sidesof this centered position. Furthermore, the jaw includes two lateralwings with an unlocking mechanism that is not shown in the figures.These elements are known, and are secondary with respect to theinvention.

[0055] The retaining element further includes a support element 62provided for the boot. The support element 62 is affixedly connected tothe jaw 56, and it is laterally movable with the displacements of thejaw.

[0056] A set of ramps is further provided between the jaw and the cover,the support element and the body. A first ramp 63 is located between theupper portion of the jaw and the cover 60. In fact, the ramp includestwo similar portions, each having two surfaces 63 a, 63 b, 63 c, 63 d,respectively, converging two by two toward the vertices 63 e, 63 f.

[0057] When the jaw is in the centered position, aligned with thelongitudinal axis of the ski, rollers 64 and 65 mounted on the cover 60are facing the vertices 63 e and 63 f of the ramp. The surfaces 63 a and63 c or 63 b and 63 d of the ramp are facing the rollers 64 and 65depending on the direction of lateral displacement of the jaw.

[0058] A second ramp 66 is located between the support element 62 andthe portion of the body located beneath the support element. As thepreceding ramp, the ramp 66 is made of two similar portions, eachincluding two surfaces, 66 a and 66 b, 66 c and 66 d, respectively. Thesurfaces converge two by two toward a recess 66 e, 66 f. When thesupport element is in the centered position, the recesses are oppositethe pins 67 and 68 projecting with respect to the upper surface of thebody.

[0059] In the centered position of the jaw, the rollers 64 and 65 are incontact with the vertices 63 e and 63 f, the recesses 66 e and 66 f arein contact with the pins 67 and 68. Depending on the direction in whichthe jaw moves laterally, and depending upon whether the bias exerted bythe boot has an upward or downward vertical force, or even a torsionalcomponent about a longitudinal axis, a portion of the ramps 64 and/or 65comes in contact with the rollers or the pins, inducing a lateralcomponent that is added to the lateral force which the boot exerts onthe jaw. This lateral component in particular compensates for thefriction existing between the boot sole, the jaw, and the supportelement.

[0060] According to the invention, the surfaces of the ramps 64 and 66have different gradients so that the compensation is more or less activedepending on the side where the jaws moves.

[0061] Thus, FIG. 11 shows the surfaces 63 a and 63 c located on a sameside with respect to the roller that is associated therewith, with asteeper gradient than the other surfaces 63 b and 63 d.

[0062] Similarly, the surfaces 66 a and 66 c located on the same sidewith respect to their associated pin as the surfaces 63 a and 63 c havea steeper gradient than the other surfaces 66 b and 66 d of the ramp.

[0063] Thus, for the same force exerted by the boot on the jaw or thesupport element, the compensation is more active if the jaw is displacedtoward the right side in the figure.

[0064] For this embodiment, the relative position of the ramps and ofthe rollers or pins could be reversed. One could also have only tworamps 63 and 66.

[0065] The invention is not limited to a front retaining element. Toillustrate this, FIGS. 11 and 12 show a rear retaining element that issaid to have a diagonal release. This type of element is disclosed inthe published French Patent Application No. 2 138 694 and U.S. Pat. No.3,876,219, the disclosures of which are incorporated by referencethereto in their entireties. Such an element is provided to react to abias of the boot having a direction that is not only vertical but alsooblique.

[0066] In a known fashion, this element includes a base 70, a retainingjaw 71 carried by a body 72 journalled with respect to the base 70 abouta transverse axle 73. The base is further movably mounted so as torotate about a vertical pivot 75 carried by a plate 76 provided to beaffixedly connected to the ski.

[0067] On the front, the plate has a fold 78 that has a ramp 79 thatextends transversely in its upper portion. The ramp has two surfaces 79a, 79 b that converge toward a slot-shaped central recess 79 c.

[0068] A roller 80 associated with the body 72 is housed in the recess79 c when the jaw is in the low retaining position and the body is inthe aligned position on the longitudinal axis of the ski.

[0069] The vertical movement of the body is guided by a retainingmechanism with threshold that will not be described in detail. When theforce exerted by the boot is greater than the retention threshold of thebody, the body rises, the roller comes out of the recess 79 c, thushaving the possibility of rolling over one of the surfaces 79 a or 79 bdepending on the direction in which the boot drives the body.

[0070] According to the invention, the surfaces 79 a and 79 b have adifferent gradient, so that the compensation induced by the ramp 79 ismore active on one side than on the other.

[0071] According to the embodiment shown, the surface 79 b is moreinclined. Concurrently, the edge that demarcates the recess 79 c isslightly lower on the side of this surface 79 b, so that thecompensation induced by the surface 79 b is active more quickly in thecase of a fall with a diagonal component on this side.

[0072] The invention is not limited to the constructional modesdescribed, and numerous variations are possible. In fact, theconstructional modes illustrate general features of the invention,including rendering the compensation more or less active depending onthe direction of the torsional component of the leg for a retainingelement having a jaw movable on either side of a centered position, anda compensating mechanism acting on the opening of the jaw in the case ofa torsional force.

[0073] Moreover, the invention that has been described could beassociated with a retaining element already having, by construction, anasymmetrical release depending on the direction of the torsional force,such that the two effects of asymmetry cumulate.

[0074] The instant application is based upon French Patent ApplicationNo. 00.04248, filed Mar. 29, 2000, the disclosure of which is herebyincorporated by reference thereto in its entirety, and the priority ofwhich is hereby claimed under 35 U.S.C. §119.

What is claimed is:
 1. An element for retaining a boot on a ski, saidretention element comprising: a jaw provided to releasably retain one ofthe ends of a boot on a ski, and an elastic return mechanism forexerting a force toward a centered position aligned with a longitudinaland vertical median plane of the retaining element; said jaw beinglaterally movable on either side of said centered position in responseto a force having a lateral component oriented in either of twodirections against a resistance of said elastic return mechanism; and acompensating mechanism acting on said jaw or said return mechanism so asto further facilitate opening of said jaw, said compensating mechanismhaving two active elements, either of said two active elements beingbiased as a function of the side to which said jaw moves with respect tothe vertical and longitudinal median plane, said two active elementsbeing asymmetrical with respect to the longitudinal and vertical medianplane, such that said compensating mechanism is more or less activedepending on which of said two active element is biased as a function ofa side on which said jaw moves.
 2. An element according to claim 1 ,wherein said compensating mechanism includes a transverse ramp having atleast two surfaces with a different gradients or inclinations.
 3. Anelement according to claim 2 , wherein said ramp has two surfacesconverging toward a recess, a roller being housed in said recess whensaid jaw is in said centered position, said recess being limited by twoedges of different heights.
 4. An element according to claim 1 , whereinsaid compensating mechanism includes two levers that are asymmetricalwith respect to the longitudinal and vertical median plane of theelement.